One of the disadvantages that has been paramount in connection with the use of hydraulic jacks has been the fact that the lifting capacity of the hydraulic jack has been limited by the amount of pressure that the user places on the handle of the jack. By their construction, hydraulic jacks can normally lift much heavier loads than has been thought possible. The limiting factor has been that the operator of the jack could not place sufficient force on the pump to raise such heavier loads. Accordingly, one of the principal objects of the invention is to interpose a power train between the handle of the hydraulic jack and the pump assembly so as to increase the mechanical advantage of the operator.
In another aspect of the invention, it is frequently desirable that the position of the handle in relation to the jack structure be movable so as to provide clearance for operation of the jack handle. In conventional jacks, one end of the handle assembly is normally pivoted to the jack structure while an intermediate point is pivoted to the pump assembly, and no provision is made for altering the position of the jack handle horizontally in relation to the body of the jack. Accordingly, a still further object of the invention is the incorporation of a power train between the handle of a hydraulic jack and the pump assembly designed in such a way that the entire power train and handle assembly may be rotated about a vertical axis so as to change the relationship between the handle assembly and the jack structure.
The invention possesses other objects and features of advantage, some of which, with the foregoing, will be apparent from the following description and drawings. It is to be understood however that the invention is not limited to the embodiment illustrated and described, since it may be embodied in various forms within the scope of the appended claims.